using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Collections.Generic;

namespace FreeFlow.Administration
{
	/// <summary>
	/// Collection of forms in a procedure.
	/// </summary>
	public sealed class FormCollection : DatabaseAware, IList, IBindingList, IRefreshable, IEnumerable<Form>
	{
    private List<Form> formsList;
    private string procedureName;
    private string tableName;

    /// <summary>
    /// Creates a new <see cref="ProcedureCollection"/> instance for the specified procedure.
    /// </summary>
    /// <param name="server">Server.</param>
    /// <param name="procedureName">The procedure name.</param>
    public FormCollection(Server server, string procedureName) : base(server)
    {
      this.procedureName = procedureName;
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="FormCollection"/> class for the specified map.
    /// </summary>
    /// <param name="server">The server.</param>
    /// <param name="map">The map.</param>
    public FormCollection(Server server, Map map) : base(server)
    {
      this.tableName = map.TableName;
      this.procedureName = map.ProcedureName;
    }

    private void ReadForms()
    {
      if (formsList == null)
      {
        formsList = new List<Form>();
        string whereClause = string.Empty;
        if (tableName != null)
          whereClause = string.Format("eTableName = '{0}'", tableName);
        else if (procedureName != null)
          whereClause = string.Format("eProcedureName = '{0}' AND eTableName NOT IN (SELECT eTableName FROM eMap WHERE eProcedureName = '{0}')", procedureName);

        using (IDataReader reader = Server.ExecuteReader(
          string.Format("SELECT * FROM eForm WHERE {0} ORDER BY eFormName", whereClause)))
        {
          while (reader.Read()) 
          {
            Form form = new Form(Server, procedureName, reader);
            formsList.Add(form);
          }
        }
      }
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
      ReadForms();
      return formsList.GetEnumerator();
    }

    #region IEnumerable<Form> Members

    /// <summary>
    /// Returns an enumerator that iterates through the collection.
    /// </summary>
    /// <returns>
    /// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
    /// </returns>
    public IEnumerator<Form> GetEnumerator()
    {
      ReadForms();
      return formsList.GetEnumerator();
    }

    #endregion

    /// <summary>
    /// Gets the number of forms in this collection.
    /// </summary>
    public int Count
    {
      get
      {
        ReadForms();
        return formsList.Count;
      }
    }

    /// <summary>
    /// Gets the <see cref="Form"/> at the specified index.
    /// </summary>
    public Form this[int index]
    {
      get
      {
        ReadForms();
        return (Form)formsList[index];
      }
    }

    /// <summary>
    /// Gets the <see cref="Form"/> with the specified name.
    /// </summary>
    public Form this[string name]
    {
      get
      {
        for (int i = 0; i < Count; i++)
        {
          if (this[i].Name == name)
            return this[i];
        }

        return null;
      }
    }

    #region IList Members

    /// <summary>
    /// Gets a value indicating whether the <see cref="T:System.Collections.IList"/> is read-only.
    /// </summary>
    public bool IsReadOnly
    {
      get
      {
        return true;
      }
    }

    object IList.this[int index]
    {
      get
      {
        ReadForms();
        return formsList[index];
      }
      set
      {
        throw new NotSupportedException(readOnlyListMessage);
      }
    }

    void IList.RemoveAt(int index)
    {
      throw new NotSupportedException(readOnlyListMessage);
    }

    void IList.Insert(int index, object value)
    {
      throw new NotSupportedException(readOnlyListMessage);
    }

    void IList.Remove(object value)
    {
      throw new NotSupportedException(readOnlyListMessage);
    }

    /// <summary>
    /// Determines whether the <see cref="T:System.Collections.IList"/> contains a specific value.
    /// </summary>
    /// <param name="value">The <see cref="T:System.Object"/> to locate in the <see cref="T:System.Collections.IList"/>.</param>
    /// <returns>
    /// 	<see langword="true"/> if the <see cref="T:System.Object"/>
    /// is found in the <see cref="T:System.Collections.IList"/>; otherwise, <see langword="false"/>.
    /// </returns>
    public bool Contains(object value)
    {
      ReadForms();
      return formsList.Contains((Form)value);
    }

    void IList.Clear()
    {
      throw new NotSupportedException(readOnlyListMessage);
    }

    /// <summary>
    /// Determines the index of a
    /// specific item in the <see cref="T:System.Collections.IList"/>.
    /// </summary>
    /// <param name="value">The <see cref="T:System.Object"/> to locate in the <see cref="T:System.Collections.IList"/>.</param>
    /// <returns>
    /// The index of <paramref name="value"/> if found in the list; otherwise, -1.
    /// </returns>
    public int IndexOf(object value)
    {
      ReadForms();
      return formsList.IndexOf((Form)value);
    }

    int IList.Add(object value)
    {
      throw new NotSupportedException(readOnlyListMessage);
    }

    /// <summary>
    /// Gets a value indicating whether the <see cref="T:System.Collections.IList"/> has a fixed size.
    /// </summary>
    public bool IsFixedSize
    {
      get
      {
        return true;
      }
    }

    #endregion
    #region ICollection Members

    /// <summary>
    /// Gets a value
    /// indicating whether access to the <see cref="T:System.Collections.ICollection"/> is synchronized
    /// (thread-safe).
    /// </summary>
    public bool IsSynchronized
    {
      get
      {
        return false;
      }
    }

    /// <summary>
    /// Copies the elements of
    /// the <see cref="T:System.Collections.ICollection"/> to an <see cref="T:System.Array"/>, starting at a particular <see cref="T:System.Array"/> index.
    /// </summary>
    /// <param name="array">The one-dimensional <see cref="T:System.Array"/> that is the destination of the elements copied from <see cref="T:System.Collections.ICollection"/>. The <see cref="T:System.Array"/> must have zero-based indexing.</param>
    /// <param name="index">The zero-based index in <paramref name="array"/> at which copying begins.</param>
    /// <exception cref="T:System.ArgumentNullException">
    /// 	<paramref name="array"/> is <see langword="null"/>.</exception>
    /// <exception cref="T:System.ArgumentOutOfRangeException">
    /// 	<paramref name="index"/> is less than zero.</exception>
    /// <exception cref="T:System.ArgumentException">
    /// 	<para>
    /// 		<paramref name="array"/> is multidimensional.</para>
    /// 	<para>-or-</para>
    /// 	<para>
    /// 		<paramref name="index"/> is equal to or greater than the length of <paramref name="array"/>.</para>
    /// 	<para>-or-</para>
    /// 	<para>The number of elements in the source <see cref="T:System.Collections.ICollection"/> is greater than the available space from <paramref name="index"/> to the end of the destination <paramref name="array"/>.</para>
    /// </exception>
    /// <exception cref="T:System.InvalidCastException">The type of the source <see cref="T:System.Collections.ICollection"/> cannot be cast automatically to the type of the destination <paramref name="array"/>.</exception>
    public void CopyTo(Form[] array, int index)
    {
      ReadForms();
      formsList.CopyTo(array, index);
    }

    void ICollection.CopyTo(Array array, int index)
    {
      CopyTo((Form[])array, index);
    }

    /// <summary>
    /// Gets an object that
    /// can be used to synchronize access to the <see cref="T:System.Collections.ICollection"/>.
    /// </summary>
    public object SyncRoot
    {
      get
      {
        return null;
      }
    }

    #endregion
    #region IBindingList Members

    void IBindingList.ApplySort(PropertyDescriptor property, ListSortDirection direction)
    {
      ReadForms();
      sortProperty = property;
      sortDirection = direction;
      formsList.Sort(new Comparer<Form>(sortProperty, sortDirection));
    }

    private PropertyDescriptor sortProperty;
    PropertyDescriptor IBindingList.SortProperty
    {
      get
      {
        return sortProperty;
      }
    }

    bool IBindingList.SupportsSorting
    {
      get
      {
        return true;
      }
    }

    bool IBindingList.IsSorted
    {
      get
      {
        return (sortProperty != null);
      }
    }

    void IBindingList.RemoveSort()
    {
      sortProperty = null;
    }

    private ListSortDirection sortDirection;
    ListSortDirection IBindingList.SortDirection
    {
      get
      {
        return sortDirection;
      }
    }

    #region not implemented 
    int IBindingList.Find(PropertyDescriptor property, object key)
    {
      return 0;
    }

    bool IBindingList.AllowRemove
    {
      get
      {
        return false;
      }
    }

    bool IBindingList.SupportsSearching
    {
      get
      {
        return false;
      }
    }

    private ListChangedEventHandler listChanged;
    event ListChangedEventHandler IBindingList.ListChanged
    {
      add { listChanged += value; }
      remove { listChanged -= value; }

    }

    bool IBindingList.SupportsChangeNotification
    {
      get
      {
        return false;
      }
    }

    object IBindingList.AddNew()
    {
      return null;
    }

    bool IBindingList.AllowEdit
    {
      get
      {
        return false;
      }
    }

    void IBindingList.RemoveIndex(PropertyDescriptor property)
    {
    }

    void IBindingList.AddIndex(PropertyDescriptor property)
    {
    }

    bool IBindingList.AllowNew
    {
      get
      {
        return false;
      }
    }

    #endregion
    #endregion
    #region IRefreshable Members

    /// <summary>
    /// Refreshes the list of forms.
    /// </summary>
    public void Refresh()
    {
      formsList = null;
    }

    #endregion
  }
}
